STP ShaliBond APP
A cold-applied, torch-free adhesive that turns standard APP membranes into a virtually self-adhesive waterproofing system.
What is it?
A black, thixotropic synthetic rubberised adhesive from STP, formulated to bond APP-modified bituminous membranes onto concrete, metal and existing bitumen surfaces without any flame or heating.
Where is it used?
Roofs and terraces, corrugated asbestos or metallic sheet roofing, and any waterproofing job where torching is banned, hazardous or simply impractical.
Why use it?
It removes the open flame from membrane laying, which means no LPG cylinders on the roof, safer work near occupied buildings, and a cleaner, faster fix in tight or awkward spots.
How is it applied?
Stir well, brush or trowel a uniform coat onto the prepared substrate and the peeled membrane, let the solvent flash off until touch-dry but tacky, then press the membrane down and lap joints 100 mm.
About STP ShaliBond APP
ShaliBond APP is STP’s answer to one of the most common headaches on an APP membrane job: the torch. Conventional atactic polypropylene (APP) membranes are bonded by melting their underside with an open flame, which is fine on an open podium slab but a genuine problem on a fragile asbestos roof, next to a running plant, or in a service duct where a naked flame is simply not allowed. ShaliBond APP is a cold-applied synthetic rubberised adhesive that does the same bonding job chemically instead of thermally. Brush or trowel it on, and it effectively converts a standard release-film APP membrane into a virtually self-adhesive sheet.
Because the adhesive is built on a synthetic rubber base, the bond it forms is not brittle. It stays elastic enough to move with the deck as concrete, metal or timber expands and contracts through the day-night and seasonal cycles that Indian roofs go through, without the bond line cracking or peeling. For contractors and consultants, that combination — a flame-free method plus a flexible, high-strength bond — is what makes it useful on the jobs where a torch-on system would either be refused on safety grounds or would deliver a poor, patchy bond. Space Arc supplies and applies ShaliBond APP as part of complete STP waterproofing build-ups across Delhi NCR and pan-India.
The technical insight
The adhesive works by carrying a synthetic rubber and bitumen blend in a solvent that keeps it as a workable thixotropic liquid in the tin. Once brushed out, the solvent evaporates and the coat passes through a short open window — touch-dry in roughly 5 to 15 minutes — where it becomes firm to the touch yet remains aggressively tacky. Bedding the membrane into the film while it is in this tacky state is what develops the bond: the rubberised layer grips both the substrate below and the membrane’s bitumen underside above, effectively welding sheet to deck through adhesion rather than heat. The high rubber content (solid content is above 55% by weight) is deliberate — it is what gives the cured film its elasticity, so the joint flexes with substrate movement instead of shearing. Full strength develops over 3 to 4 days of curing, by which point the membrane-to-membrane lap shear strength exceeds 3 MPa and the bond to concrete is so complete that a pull test fails the membrane itself before the adhesive line lets go.
Where it is used
- Cold-bonding APP torch-on membranes to RCC roof and terrace slabs where an open flame is undesirable
- Waterproofing over corrugated asbestos-cement roofing that cannot take direct torch heat
- Bonding membranes onto metallic and profiled steel sheet roofs
- Membrane laying in occupied buildings, hospitals, plants and warehouses where hot-work permits are hard to obtain
- Small, congested or awkward areas — parapet returns, upstands, gutters and pipe surrounds — where a torch is clumsy or hazardous
- Overlaying and re-bonding onto sound existing bituminous membrane during refurbishment
- Priming and sealing pores on the concrete surface before the membrane is set down
- Confined zones such as ducts, shafts and basements where LPG cylinders and naked flame are prohibited
Key advantages
- Fully cold-applied — no torch, no LPG cylinders and no hot-work permit required on site
- Turns a standard release-film APP membrane into a virtually self-adhesive sheet
- Synthetic rubber base keeps the bond flexible, so it moves with substrate expansion and contraction
- Very high adhesion — bond to concrete is strong enough that the membrane fails before the glue line
- Safe to use on fragile asbestos and thin metal roofs that would be damaged by direct flame
- Doubles as a pore sealer on concrete, improving the contact surface for the membrane
- Easy to apply by brush, trowel or spray with ordinary site labour
- Ideal for refurbishment, tight geometry and occupied premises where torching is impractical
Limitations & considerations
- Solvent-based and flammable — keep away from ignition sources and ensure good ventilation during use
- Not a standalone waterproofing coating; it is a bonding adhesive that always works with an APP membrane
- Needs a clean, dry, dust- and grease-free surface — poor preparation directly weakens the bond
- Full cure takes 3 to 4 days, so bonded areas should be protected from traffic and standing water until set
- Should be applied within a substrate temperature of about 10 to 40°C; very cold or very hot decks affect the open time
- Solvent odour during application makes ventilation essential in enclosed or poorly aired spaces
Selection & best practice
Start with surface preparation, because the bond is only as good as what it grips. Remove all dust, loose flakes, oil and grease with dry compressed air or by mechanical cleaning, and make sure the deck is dry before you begin. Stir the adhesive thoroughly to redistribute the solids. Apply a uniform coat by trowel or brush to both the substrate and to the underside of the TarFelt APP membrane after peeling off its release film. Let both coats flash off until they are touch-dry but still highly tacky — this open window, roughly 5 to 15 minutes, is the moment to bond; too wet and the sheet slides, too dry and adhesion drops. Lay the membrane and press it down uniformly to squeeze out air and wet out the joint, keeping a 100 mm overlap at every membrane-to-membrane lap. Work within a 10 to 40°C substrate temperature, allow 3 to 4 days for the bond to reach full strength, and clean all tools immediately with STP Thinner before the adhesive sets.
Specifications
| Form & Colour | Black thixotropic liquid |
| Base | Synthetic rubberised adhesive |
| Solid Content | > 55% by weight |
| Density | 1.0 ± 0.05 g/cc |
| Viscosity | 1000 – 3000 cps |
| Theoretical Coverage | 0.3 – 0.40 kg/m² (surface dependent) |
| Touch Drying Time | 5 – 15 minutes |
| Lap Shear Strength (membrane-to-membrane, 7 days) | > 3 MPa |
| Flash Point | > 23°C |
| Packaging | 20 kg & 200 kg drums |
| Shelf Life | 12 months (sealed, 5 – 38°C) |
Industry use cases
Industrial & Plant Roofing
Waterproofing over asbestos-cement and metal sheet roofs on factories and warehouses where an open flame near stored goods or process areas is a non-starter.
Healthcare & Institutional
Terrace and roof waterproofing on hospitals, schools and offices that stay occupied, avoiding the hot-work permits and evacuation risk that torching brings.
Roof Refurbishment
Re-bonding new APP membrane over sound existing bitumen felt during re-roofing, without the fire risk of torching onto an aged, unknown substrate.
Congested & Confined Details
Parapets, gutters, upstands, ducts and pipe surrounds where a torch is awkward or prohibited, and a brush-applied cold adhesive gives cleaner detailing.
Residential Terraces
Home and apartment terrace waterproofing where owners want a safe, flame-free membrane system laid without gas cylinders on the roof.
Frequently asked questions
Does ShaliBond APP replace the need to torch the membrane?
How much ShaliBond APP will I need per square metre?
Is it a waterproofing coating on its own?
Can it be used on asbestos and metal sheet roofs?
How long before the bonded membrane is fully cured?
What pack sizes does Space Arc supply?
How we position STP ShaliBond APP
ShaliBond APP is the cold-bonding partner within STP’s roofing system: pair it with an STP TarFelt APP membrane, and use an STP bituminous primer to seal porous decks before adhesive is applied. Where the deck is exposed and UV-facing, a liquid-applied STP membrane may be a better finish than a bonded sheet. Across our other brands, clients weighing a torch-on approach often look at Fosroc’s Proofex Torchseal APP membranes, while those wanting a brush-applied cold system without any sheet at all consider Fosroc Nitoproof rubberised bitumen coatings — our team can advise which route suits the substrate, exposure and site safety constraints.
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